Automatic cleaners for cleaning swimming pools

ABSTRACT

An automatic pool cleaner of the type having an elongated body ( 11 ) with an inlet, a flexible seal ( 32 ) mounted on an end of the elongated body to bear against the surface of the wall or floor of the pool, a flip-flop valve ( 25 ) positioned adjacent the inlet ( 21 ) of the elongated body ( 11 ) and capable of moving back and forth between two extreme positions for controlling the flow of water through the elongated body and in so doing producing a “water hammer effect” which acts on the automatic pool cleaner to propel it across the surface and wherein the flip-flop valve includes a substantially wedge shaped hammer ( 25 ) formed by two spaced substantially triangular sides interconnected by a central body narrower than the sides and a continuous end surface ( 61 ) connecting respective ends of the substantially triangular side pieces such that the hammer has continuous sides and cavities between the sides due to the central body being narrower than the sides, the continuous end surface ( 61 ) having indentations ( 65 ) to be engaged by flow of water around the hammer ( 25 ) and into the inlet ( 21 ) of the elongated body ( 11 ) to aide the flip-flop action.

[0001] This invention relates to automatic pool cleaners of the type adapted to be connected to a flexible hose, which is connected to the inlet of pump circulating water through the pool. One such cleaner is marketed throughout Australia and other countries under the trade mark “Zoltans Automatic Pool Cleaner”. Another version is sold under the trade mark “Kreepy Krauly”. One version of the Kreepy Krauly cleaner is described in the expired Australian Patent Specification No. 505209.

[0002] Such automatic pool cleaners can comprise a body having an inlet, a flexible seal mounted on the body to bear against the surface of the wall or floor of the pool, a flip-flop valve capable of moving back and forth between two extreme positions for controlling the flow of water through a body and in doing so produce a water hammer effect which acts on the automatic cleaner to propel it across the surface. An elongated member connects the body to the inlet end of a flexible hose. The elongated member has two passages formed by two parallel tubes through which the water flows alternately.

[0003] It has been found that the flip-flop valve performance is substantially and unexpectedly affected by small changes in structure and thereby substantially affects the efficiency of the automatic pool cleaner. It has been found that the efficiency of the automatic pool cleaner can be substantially improved if the hammer forming the critic al part of the flip-flop valve is altered.

[0004] It is therefore an object of the invention to devise an improved automatic pool cleaner, which may be effective with a less powerful suction means than is presently possible.

[0005] It is also an object of the invention to provide anb improved automatic pool cleaner which overcomes or ameliorates one or more disadvantages of known automatic pool cleaners.

[0006] Thus according to the present invention there is provided an automatic pool cleaner of the type having an elongated body with an inlet, a flexible seal mounted on an end of the elongated body to bear against the surface of the wall or floor of the pool, a flip-flop valve positioned adjacent the inlet of the elongated body and capable of moving back and forth between two extreme positions for controlling the flow of water through the elongated body and in so doing producing a “water hammer effect” which acts on the automatic pool cleaner to propel it across the surface and wherein the flip-flop valve includes a substantially wedge shaped hammer formed by two spaced substantially triangular sides interconnected by a central body narrower than the sides and a continuous end surface connecting respective ends of the substantially triangular side pieces such that the hammer has continuous sides and cavities between the sides due to the central body being narrower than the sides, the continuous end surface having indentations to be engaged by flow of water around the hammer and into the inlet of the elongated body to aid the flip-flop action.

[0007] The indentations can be of the order of 20 to 30% of the end surface allowing ready flow around the hammer while providing sufficient reaction of the flow to aid the flip-flop action. Preferably the end surface is curved with a radius of curvature at least equal to the length of the wedge shaped hammer.

[0008] In one form the indentations can be spaced circular indentations extending in two lines on either side of the centre longitudinal centre of the end surface. The indentations can be substantially hemispherical such that their depth is of the order of about their radius.

[0009] The substantially wedge shaped hammer can be less than 80 grams and preferably less than 75 grams.

[0010] Also according to the present invention there is provided a flip-flop valve able to be used in an automatic pool cleaner of the type having an elongated body with an inlet, a flexible seal mounted on an end of the elongated body to bear against the surface of the wall or floor of the pool, wherein the flip-flop valve can be positioned adjacent the inlet of the elongated body and move back and forth between two extreme positions for controlling the flow of water through the elongated body of the automatic pool cleaner and in so doing producing a “water hammer effect” which acts on the automatic pool cleaner to propel it across the surface and wherein the flip-flop valve includes a substantially wedge shaped hammer formed by two spaced substantially triangular sides interconnected by a central body narrower than the sides and a continuous end surface connecting respective ends of the substantially triangular side pieces such that the hammer has continuous sides and cavities between the sides due to the central body being narrower than the sides, the continuous end surface having indentations to be engaged by flow of water around the hammer and into the inlet of the elongated body to aid the flip-flop action.

[0011] The indentations can be of the order of 20% to 30% of the end surface allowing ready flow around the hammer while providing sufficient reaction of the flow to aid the flip-flop action. Preferably the end surface is curved with a radius of curvature at least equal to the length of the wedge shaped hammer.

[0012] In one form the indentations can be spaced circular indentations extending in two lines on either side of the centre longitudinal centre of the end surface. The indentations can be substantially hemispherical such that their depth is of the order of about their radius.

[0013] The substantially wedge shaped hammer can be less than 80 grams and preferably less than 75 grams.

[0014] In use a light hammer provides a faster flip-flop and thereby a greater suction. Further the lighter the hammer the smoother the action as there is less vibration which results in less lateral knocking motion that could break the suction seal of the automatic pool cleaner from the pool. This is particularly advantageous in cleaning higher up the walls of the pool. The spaced circular indentations provide unexpectedly substantial initiation improvement and increased suction seal through providing flow friction points and/or turbulence effect and provide continuing aid in the flip-flop action of the hammer valve. It avoids the known problem of earlier cleaners of using heavier flip-flop valves such as greater than 90 grams to make use of the weight to initiate the flip-flop action when suction has begun. Such systems were particularly ineffective in cleaning walls of pools and often had suction seal broken by a violent “water hammer effect”. Further such systems require a large pool vacuum system to cope with the weight and to compensate for the suction seal breakages.

[0015] In order to explain the invention more clearly an embodiment will be described by way of illustration only with reference to the drawings wherein:

[0016]FIG. 1 is a perspective view of a known automatic pool cleaner;

[0017]FIG. 2 is a cross sectional view of the automatic pool cleaner of FIG. 1;

[0018]FIG. 3 is a aside elevation of a flip-flop valve in accordance with the invention for use in the automatic pool cleaner of FIG. 1;

[0019]FIG. 4 is a perspective view of the flip-flop vale of FIG. 3.

[0020] Referring to FIGS. 1 and 2 of the drawings there is shown an elongated body 11 of an automatic pool cleaner 15 having two coextending tubular chambers 16, 17 meeting at a top U-shaped connector 19 that feeds to a suction pump (not shown). At the lower end of the elongated body 11 the two coextending tubular chambers 16, 17 have angled inlet openings from a valve chamber 21 in which a wedge shaped hammer valve member 25 is housed so that it can move back and forth with a flip-flop action about a longitudinal axis extending between the coextension of the tubular chambers 16,17. The flip-flop action is also around a lateral pivot end at the narrow apex of the wedge shaped hammer valve member 25 and is able to flip-flop between positions in which the hammer valve member alternately bears against and closes the inlet end of first passage or fluid flow path formed by first coextending tubular chambers 16, to a position in which the hammer valve member25 bears against the inlet end and closes a second passage or fluid flow path formed by second coextending tubular chambers 17. The movement of the hammer valve member 25 from one position to the other produces a “water hammer effect” which acts on the cleaner to propel it across the surface to be cleaned.

[0021] The upper ends of the tubes 14 and 15 are connected to a chamber 17 the upper end of which is pivotally connected to the inlet end of a flexible hose (not shown) by means of a coupling. The base of the cleaner body is provided with wings 30, 31 and pleated flexible seal 32, which bears on the surface to be cleaned. It is also provided with one or more inlets while the valve chamber may be provided with a baffle. A float assembly 42 is pivotally mounted on the body of the cleaner.

[0022] In accordance with the invention, the hammer has the construction shown in FIGS. 3 and 4 to provide a more efficient automatic pool cleaner. The hammer 51 comprises a substantially wedge shape formed of two spaced substantially triangular planar sides 54, 55 interconnected by a central body 71 narrower than the sides 54, 55 and extending normal to the planar extension of the sides 54, 55. The two spaced substantially triangular planar sides 54,55 each has diverging straight sides 57, 58 beginning at a narrow pivot end 56 and ending at a continuous curved end 59 such that the substantially triangular planar sides 54, 55 each form a sector of a circle.

[0023] The curved end 59 of the two spaced substantially triangular planar sides 54, 55 have a connecting portion extending normal to the spaced substantially triangular sides 54, 55 and to the narrow interconnecting central body 71. This connecting portion 71 has a curved surface 61 corresponding with the curved ends 59 of the two spaced substantially triangular sides 54, 55 and extending therebetween to form the substantially wedge shape with curved end. The outer end of the two spaced substantially triangular planar sides 54, 55 further include a parallel protruding ridge 82 extending with linear front edges about 1 to 2 millimeters out from the outer planar side surfaces 54, 55 and extending to the curved ends 59.

[0024] The interconnecting central body 71 extends substantially in a single plane with outer surfaces extending between respective spaced substantially triangular side pieces 54, 55. The outer surfaces have a continuous substantially triangular sine wave formation with as wavelength of the order of 18 millimeters and amplitude of about 3 millimeters. The flip-flop valve hammer 51 has continuous sides 54, 55 and cavities between the sides due to the central body 71 being narrower than the sides.

[0025] The curved surface 61 of the end of the flip-flop valve hammer 51 has indentations in order to allow flow of water around the curved surface 61 of the hammer 51 and into inlet end of first passage or fluid flow path formed by first coextending tubular chambers 16 and flip-flop hammer 51 to allow flow into inlet end of second passage or fluid flow path formed by second coextending tubular chambers 17. This results in a pulsing to provide the “water hammer effect”. The curved surface 61 has six spaced indentations 65 in two lines of three on either side of the central longitudinal line of symmetry. The indentations are about 9 to 10 millimeters in diameter with a depth in the order of 5 to 10 millimeters.

[0026] The angle of divergence of the straight sides 57, 58 is about 25° and the length of the two spaced substantially triangular planar sides 54, 55 is of the order of 90 millimeters with the spacing being about 35 millimeters. This results in the spacing between the respective curved ends 59 of the two spaced substantially triangular planar sides 54, 55 being about 38 millimeters. Further the footprint provided by the curved surface 61 is rectangular with dimensions of about 38 millimeters by 50 millimeters.

[0027] The hammer is made from mouldable synthetic materials that are suitable for enduring the harsh conditions within the automatic pool cleaner and harsh chemicals such as chlorine. It also has a weight of the order of about 70 grams. To achieve the moulded configuration the hammer is made in two exactly similar moulds each forming parts of each side wall 54, 55, part of the central body 71 therebetween having a substantially triangular sine wave surface, and part of the end surface 61. Two of the partial units formed by the moulds can be joined back-to-back along central mould line 91.

[0028] The above is a description of a preferred embodiment of the present invention. Various changes and modifications can be made without inventiveness by a person skilled in the art and without departing from the spirit and scope of the present invention and such are included within the scope of the invention as defined by the following claims. 

1. An automatic pool cleaner of the type having an elongated body with an inlet, a flexible seal mounted on an end of the elongated body to bear against the surface of the wall or floor of the pool, a flip-flop valve positioned adjacent the inlet of the elongated body and capable of moving back and forth between two extreme positions for controlling the flow of water through the elongated body and in so doing producing a “water hammer effect” which acts on the automatic pool cleaner to propel it across the surface and wherein the flip-flop valve includes a substantially wedge shaped hammer formed by two spaced substantially triangular sides interconnected by a central body narrower than the sides and a continuous end surface connecting respective ends of the substantially triangular side pieces such that the hammer has continuous sides and cavities between the sides due to the central body being narrower than the sides, the continuous end surface having indentations to be engaged by flow of water around the hammer and into the inlet of the elongated body to aid the flip-flop action.
 2. An automatic pool cleaner according to claim 1 wherein the indentations are of the order of 20 to 30% of the end surface allowing ready flow around the hammer while providing sufficient reaction of the flow to aid the flip-flop action.
 3. An automatic pool cleaner according to claim 1 wherein the end surface is curved with a radius of curvature at least equal to the length of the wedge shaped hammer.
 4. An automatic pool cleaner according to claim 1 wherein the indentations can be spaced circular indentations extending in two lines on either side of the centre longitudinal centre of the end surface.
 5. An automatic pool cleaner according to claim 1 wherein the indentations are substantially hemispherical such that their depth is of the order of about their radius.
 6. A flip-flop valve able to be used in an automatic pool cleaner of the type having an elongated body with an inlet, a flexible seal mounted on an end of the elongated body to bear against the surface of the wall or floor of the pool, wherein the flip-flop valve can be positioned adjacent the inlet of the elongated body and move back and forth between two extreme positions for controlling the flow of water through the elongated body of the automatic pool cleaner and in so doing producing a “water hammer effect” which acts on the automatic pool cleaner to propel it across the surface and wherein the flip-flop valve includes a substantially wedge shaped hammer formed by two spaced substantially triangular sides interconnected by a central body narrower than the sides and a continuous end surface connecting respective ends of the substantially triangular side pieces such that the hammer has continuous sides and cavities between the sides due to the central body being narrower than the sides, the continuous end surface having indentations to be engaged by flow of water around the hammer and into the inlet of the elongated body to aid the flip-flop action.
 7. A flip-flop valve according to claim 6 wherein the indentations can be of the order of 20% to 30% of the end surface allowing ready flow around the hammer while providing sufficient reaction of the flow to aid the flip-flop action.
 8. A flip-flop valve according to claim 6 wherein the end surface is curved with a radius of curvature at least equal to the length of the wedge shaped hammer.
 9. A flip-flop valve according to claim 6 wherein the indentations are spaced circular indentations extending in two lines on either side of the centre longitudinal centre of the end surface and wherein the indentations are substantially hemispherical such that their depth is of the order of about their
 10. A flip-flop valve according to claim 6 wherein the curved end of the two spaced substantially triangular planar sides have a connecting portion extending normal to the spaced substantially triangular sides and to the narrow interconnecting central body with the connecting portion has a curved surface corresponding with the curved ends of the two spaced substantially triangular sides and extending therebetween to form the substantially wedge shape with curved end and the outer end of the two spaced substantially triangular planar sides further including a parallel protruding ridge extending with linear front edges about 1 to 2 millimeters out from the outer planar side surfaces and extending to the curved ends.
 11. A flip-flop valve according to claim 6 wherein the interconnecting central body extends substantially in a single plane with outer surfaces extending between respective spaced substantially triangular side pieces.
 12. A flip-flop valve according to claim 6 according to claim 1 wherein the outer surfaces have a continuous substantially triangular sine wave formation with as wavelength of the order of 18 millimeters and amplitude of about 3 millimeters.
 13. A flip-flop valve according to claim 6 wherein the flip-flop valve hammer has continuous sides and cavities between the sides due to the central body being narrower than the sides.
 14. A flip-flop valve according to claim 6 wherein the curved surface of the end of the flip-flop valve hammer has indentations in order to allow flow of water around the curved surface of the hammer and into inlet end of first passage or fluid flow path formed by first coextending tubular chambers and flip-flop hammer to allow flow into inlet end of second passage or fluid flow path formed by second coextending tubular chambers resulting in a pulsing to provide the “water hammer effect”.
 15. A flip-flop valve according to claim 6 wherein the curved surface has six spaced indentations in two lines of three on either side of the central longitudinal line of symmetry.
 16. A flip-flop valve according to claim 6 wherein the indentations are about 9 to 10 millimeters in diameter with a depth in the order of 5 to 10 millimeters.
 17. A flip-flop valve according to claim 6 wherein the angle of divergence of the straight sides is about 25° and the length of the two spaced substantially triangular planar sides is of the order of 90 millimeters with the spacing being about 35 millimeters resulting in the spacing between the respective curved ends of the two spaced substantially triangular planar sides being about 38 millimeters. Further the footprint provided by the curved surface is rectangular with dimensions of about 38 millimeters by 50 millimeters.
 18. A flip-flop valve according to claim 6 wherein the hammer is made from mouldable synthetic materials that is suitable for enduring the harsh conditions within the automatic pool cleaner and harsh chemicals such as chlorine.
 19. A flip-flop valve according to claim 6 having a weight of the order of about 70 grams. 